Spark plug



July 14, 1925. 1,544,110

M. RQTHBERG ET AL SPARK PLUG Filed Nov. 29. 1921 /f f F77, 2.

Patented July 14, 1925.

UNITED [STATES PATENT oFFlcE-p.

MURRAY ROTHBERG AND JOHN LA CAVA, 10F. BROOKLYN, Nnwvonx. f

,SPARK PLUG.

Application filed November :29, 1921. serial No- 518,585,...A

To all whom t may concern Be it known that we, MURRAY ROTHBERG and JOHN LA CAVA, Vcitizens of the United States, residing at Brooklyn, inthe county of Kings and State ofNew York, have invented certain new and useful Improvey, ments in Spark Plugs; and we do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art Vto which it appertains to make and use the same.

The invention relates to spark plugs for the ignition system'ofexplosive engines and its primary intent is the provision of a double-ended spark plug which maybe reversed thereby'performing the same otiicey as two independent sparkpl'ugsat practically the same cost of a single spark plug.

The invention consists of a 'shell or body provided at opposite ends with adjustableV electrodes, a corev of insulating material within the shell, an electrode carried by the core and projecting beyondl the ends thereof to cooperate with the electrodes ofLthef shell, and a cap detachabl7 fitted to either end of the shell and provided with a bindingrv post to make electrical connection with either end of the electrode carriedv by the core according to which ever end of the shell the cap is applied to. Other objects and advantages will be apparent and suggest themselves as the nature yof the invention is understood.

l/Vhile the drawings illustrate an embodiment of the invention it is to be understood that in adapting the same to meet 'different conditions andrequirements, various changes in the form, proportion andminor details of construction may be lresorted to without departing/from the nature of the invention. i'

Referring to the accompanying drawings forming apart of thel application,V

Figure 1 is an elevation of a spark plug embodying the invention,

Figure 2 isr a central longitudinal section thereof, 4

','Figure 3 is an elevation of the shell or bod vthe cap bein omitted,and' v 11 igure 4 is an en view of the cap.,`

Corresponding and like parts are pre ferred to in the following ldescription and designated'in the several views of the drawings by like'reference characters.

TheV spark plug comprises a shell or body 1 having an v'inner shoulder 2 and a centrally disposed polygonal portion for the reception ofa wrench or, Spanner. Opposite endportions of the shell 1 are externally screw threaded as at 1a to admit of either end being coupled to the engine in the usual way. Each end of the shell or body 1 is provided with an electrode 3 which is adjustable to admit'of either electrode being turnedaside to be out'of the way and the otheruelectrode to be moved into operative position. The two positions of the electrodes are shown. most clearly in'Figures 2 and 3.

`V` Acoret of insulating material is disposed within the shell or body 1 andhas-an outer shoulder 5- ,which engages the inner shoulder 2,'a nut 6 threaded into the shell serving'n to secure the core 4: within vthe shell, 'as clearly indicated in Figure2. A gasket is fitted aboutk the shouldered portion 5 of thev corea and comprises a metal sleeve' 15 and packing 16, the ends of the sleeve 15 being crimped about the ends of the part 5 and the packing 16 being disposed to come between adjacent shoulders 2 and 5. An electrode 7 is secured centrally 'within the core 4; and its 'end portions project beyond the core and are externally screw threaded. Points 8 are fitted to oppositeends ofthe electrode 7 and form extensions thereof and are adapted to cooperate with the electrodes -The tubular extensionl() is'likewise of insulating material and is preferably separate.t from the cap. g n

A piece of felt 20, or like material, is let into a notch formed in the inner end of the '3. kWashers 17 are held against the ends of vthe core 4 by nuts 18 threaded on the projecting ends of the electrode 7.

-` A cap 9 of insulatingV material is adapted Y A binding post is carried by the cap 9 andY comprises a threaded stem 11 and a tubular portion-12, the latter b eing disposed within thef tubular extension 10 .and the stem 11 projecting beyond the. end of the cap Aand receiving` a washer 13 and a binding nutld, the v.washer v13 comprising suitable packing having a vmetal insert crimped there about, and the nut llloperating as means for securing the usual lead wireto the spark plug. The tubular `portion 12 is internally screw y threaded to .match the externally threaded portion 19 ofthe electrode 7,;whereby to secure thecap tothe shell orV body 1 and insure positive connection between the binding post .and the electrode. v

In practice, the lcap Qisiitted to an end of the shell, or body, the electrode 3 housed by the cap being turned aside, as indicated in Figure 2 and t-he electrode 3 of the exposed end being'turned toV cooperate withthe point 1 Slof the electrode 7 tokform the usual spark Agaprfor a purpose well understood. In the 'event of the 'spark plug fouling at/one end, vor .failing to function` properly, the cap 9 may be detached'and thebodyv of the plug andy the electrodes 3 reversed and the cap applied to the end previously coupledto the. engine with theI result that'the plug ypresents a new 'working end in substantially ,the saine manner asl a new plug, .thereby saving time and obviating the necessity of carrying extra plugs :fortan emergency .and besides minimizing the cost, since: -the article maybe ,provided at substantially the `same ,cost asl the ordinary single Vspark plug. What is claimed is:V t. u f

1. A reversible spark plug comprising a shell and a core l,of insulating material secured'v within the shell and. having project-- ing end portions spaced from the shell, ran electrode carriedbythe vcore andY at each end coactingwith the shell to ,provide a sparkgap, a cap constituting a terminal for .a `conductor and adapted to be fitted to eitherend ofthe shell, a tubular element carried by the cap and adapted to receive either end ofthe core, and a wiperl carried byJ said tubular element for removing soot or 'other accumulation tending to foul and *short l circuit the plug.

"2: A sparklplug comprising a shella core of insulating material within the shell and having its end portions spaced therefrom, an electrode carried by the core and coacting with the shell to provide spark gaps adjacent said portions, a cap 'constituting a binding .means .for a conductor and adapted vto selectively olose either end of "the shell,

and a wiper carried by the cap adapted to engage thel adjacent surfaces of the core Ito remove ysoo't 'and-the' like 5Jtherefrom when` removing or replacing the cap. Y

3. A spark plug comprising a shell, a coreof'insulating,,material within the shell, an electrode carried by the core and having its end portions-providing spark gapsbetween tlie;same4 and the shell, a cap .constitut-V ing'a binding means ,for anconductor and applicable tol either'end l of the shell, V,said

cap being provided with an lelernentadapted to enter-said spaces between the shell and core, and a wiper carried byy said-element and movable withrthe capfwhen placing it in position or Vremoving it from the shell.y

4. A spark plug"comprisinglashelha core of insulatingv materialwithin theshell, an elect-rode within ,the core -andhaving itsv ends projecting beyond the core and. threaded, said electrode providing siparkrgapsbetween the same Aand `the shell, a capl constituting a f spark yplughaving a shell, a core of insulation thereinzspaced at `the sides of its ioo end portions from the inner-wall of the shell, Y

andan electrode :carried by. the core, electrodes carriedby .theshell onevadj acent each end,v to-provide spark vgaps .between the same and the first electrode,acap applicable to either end of the electrode havingra binding Yp ostthereon for a conductor, a ltube .carried Y ,by .the cap disposable `in fthe spaces between the ends of the coreand the shell, said binding post :being sur-rounded by saidftube, Land the secondy mentioned electrodetbeing .movable relatively` toA ,the -vrst ,mentioned velectrode :.to accommodate theu n y recept-ion of ksaidv 4tube` with-in the plug: f f

- 6'. *A*VA spark plug havinga shellfa core of insulation thereinspaced kat the sides of v its end portions from the inner wall of the shell, andanelectrode carried bythe core, electrodes carriedbythe shell one adjacent .each end. to V,provide `spark gaps between' the same andthe first electrode,acapapplicable to-either endiof the electrode havinga binding post thereon for a conductor, a tube .carried by .the cap ,disposable in the*k Vspaces between theends ofthe/corefand the shell,

said bindinglpostbeing lsurrounded by said tube, the second mentioned electrode being movable relatively to the first mentioned electrode to accommodate the reception of `said tube within the plug, said tube extending inwardly beyond said binding post, and a Wiper carried by the tube adjacent its inner end and adapted to clean the plug adjacent the Spark gap through'iemoval and application of the cap.

In testimony whereof We affix our signatures in the presence of tWo Witnesses.

MURRAY ROTHBERG. JOHN LA o AvA.

Witnesses:

C. P. SMITH, J. R. MAURNO. 

